3.2.4 Effect of plateau pika disturbance intensity on soil organic carbon stock
Accounting for an overall scale effect, the soil organic carbon stock showed a significant unimodal curvilinearity as the disturbance intensity increased (Figure. 9A). Considering site-scale effects, the soil organic carbon stock also showed significant unimodal curvilinearity at each site with increasing disturbance intensity (Figure. 9B).
3.2.5 Effects of plateau pika disturbance intensity on soil total nitrogen, phosphorus andpotassium stocks
When data from the five sites were analyzed together, the soil total nitrogen (Figure 10A), phosphorus (Figure. 11A) and potassium (Figure. 12A) stocks increased and then decreased as the disturbance intensity increased.
When data from each site were analyzed separately, the relationship between the disturbance intensity and soil total nitrogen (Figure. 10B) and phosphorus (Figure. 11B) stocks was similar at each site, in agreement with the overall scale effect, whereas the relationship between the disturbance intensity and soil total potassium stock was different among five sites, in which the response of soil total potassium stock to the disturbance intensity was similar to the overall scale effect at Luqu and Gonghe (Figure. 12B), whereas it showed no obvious trends at Gangcha, Haiyan and Qilian as the disturbance intensity increased.